Cellular telecommunications is one of the fastest growing and most demanding telecommunications applications. Today it represents a large and continuously increasing percentage of all new telephone subscriptions around the world.
With reference now to FIG. 1 of the drawings, there is illustrated a Global System for Mobile Communications (GSM) Public Land Mobile Network (PLMN), such as wireless network 10, which in turn is composed of a plurality of areas 12, each with a Mobile Services Switching Center (MSC) 14 and an integrated Visitor Location Register (VLR) 16 therein. The MSC/VLR areas 12, in turn, include a plurality of Location Areas (LA) 18, which are defined as that part of a given MSC/VLR area 12 in which a mobile station (MS) 20 may move freely without having to send update location information to the MSC/VLR area 12 that controls the LA 18. Each Location Area 12 is divided into a number of cells 22. Mobile Station (MS) 20 is the physical equipment, e.g., a car phone or other portable phone, used by mobile subscribers to communicate with the wireless network 10, each other, and users outside the subscribed network, both wireline and wireless.
The MSC 14 is in communication with at least one Base Station Controller (BSC) 23, which, in turn, is in contact with at least one Base Transceiver Station (BTS) 24. The BTS 24 is the physical equipment, illustrated for simplicity as a radio tower, that provides radio coverage to the geographical part of the cell 22 for which it is responsible. It should be understood that the BSC 23 may be connected to several BTSs 24, and may be implemented as a stand-alone node or integrated with the MSC 14. In either event, the BSC 23 and BTS 24 components, as a whole, are generally referred to as a Base Station System (BSS) 25. It should be noted that the BSC 23 functionality can be included within the MSC 14, instead of being implemented as a separate node as shown in FIG. 1.
With further reference to FIG. 1, the PLMN Service Area or wireless network 10 includes a Home Location Register (HLR) 26, which is a database maintaining all subscriber information, e.g., user profiles, current location information, International Mobile Subscriber Identity (IMSI) numbers, and other administrative information. The HLR 26 may be co-located with a given MSC 14, integrated with the MSC 14, or alternatively can service multiple MSCs 14, the latter of which is illustrated in FIG. 1.
The VLR 16 is a database containing information about all of the Mobile Stations 20 currently located within the MSC/VLR area 12. If an MS 20 roams into a new MSC/VLR area 12, the VLR 16 connected to that MSC 14 will request data about that MS 20 from its home HLR database 26 (simultaneously informing the HLR 26 about the current location of the MS 20). Accordingly, if the user of the MS 20 then wants to make a call, the local VLR 16 will have the requisite identification information without having to reinterrogate the home HLR 26. In the aforedescribed manner, the VLR and HLR databases 16 and 26, respectively, contain various subscriber information associated with a given MS 20.
In some instances, the MS 20 may not respond to attempts to contact it for a variety of reasons, including being powered off, being in radio shadow, congestion, etc. If the MS 20 cannot be reached, the party or application trying to contact the MS 20 normally has to retry contacting the MS 20 after a period of time. An alternative to this is for the party or application to request the network 10 to notify it of when the MS 20 is known to be available, for example, at power on, location registration, or contact by another party. This request is normally made to a control point (not shown) in the network 10 which stores data indicating the address of the party or application who requires notification.
In GSM networks, notification to the requesting application of the availability of the MS 20 normally occurs in the situation where a Short Message Service Center (SMS-C) (not shown), which has unsuccessfully attempted to deliver a short message to the MS 20, requests the HLR 26 to send an "Alert" message to the SMS-C when the MS 20 becomes available. If more than one SMS-C is requesting an "Alert" message, timers can be implemented within the network 10 to coordinate the alert procedures.
However, there are many other types of applications being developed that also need to know when an MS 20 becomes available, such as voice mail call-back, call completion, and e-mail delivery. In order to allow all the requesting applications to contact the MS 20, a management procedure needs to be implemented to notify the requesting applications in a coordinated fashion of when they can attempt to contact the MS 20. The timers currently utilized for coordinating SMS "Alert" messages do not allow for the different time needs for various types of nodes and applications.
It is, therefore, an object of the present invention to provide a system and method for coordinating terminal availability notifications for a variety of requesting nodes and applications.
It is a further object of the present invention to allow requesting nodes and applications to have a priority notification associated therewith in order to allow a control node to prioritize the notification requests.
It is still a further object of the present invention to provide a timer value for each priority associated with the requesting applications, in which each timer value corresponds to the amount of time needed for a requesting application to complete its communication function toward the terminal.